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What's the ideal nitrate level for a mixed reef tank? I've heard conflicting advice, some say 5 ppm, others say up to 20 ppm is fine. My tank's sitting at 15 ppm right now, and my Acropora seem happy, but I'm not sure if I should aim lower.

From my experience, it depends on the coral types. SPS like Acropora do better under 10 ppm, but LPS and softies can handle up to 20 ppm. What's your lighting and flow like? Those factors play a big role too.

yo, 15 ppm ain't bad if everything's chill. my zoas and hammers thrive at 15, but my montis start browning if it goes higher. test weekly and adjust feeding if it creeps up.

regrex wrote: ↑Fri Jul 11, 2025 7:47 am yo, 15 ppm ain't bad if everything's chill. my zoas and hammers thrive at 15, but my montis start browning if it goes higher. test weekly and adjust feeding if it creeps up.

Agreed. I keep mine around 10 ppm for a mixed tank. If you're heavy on SPS, maybe cut it to 5 ppm.

i run mine at 20 ppm cuz i got mostly softies. they're growing like crazy, but my one acro frag is barely hanging on. might move it to another tank.

My nitrates are always zero. Is that bad? I dose amino acids but my corals look pale.

Thanks for the input, everyone. I'll test more frequently and maybe dial back feeding a bit to see if I can stabilize around 10 ppm.

I've had success with 5-10 ppm for SPS. Higher than that and my birdsnest starts losing color. What salt mix are you using? Some have trace nitrates built in.

tender wrote: ↑Fri Jul 11, 2025 11:01 am My nitrates are always zero. Is that bad? I dose amino acids but my corals look pale.

Zero nitrates can starve corals. Try increasing feeding slightly or adding a nitrate supplement like NeoNitro. Pale colors often mean low nutrients.

if your acros are happy at 15 ppm, don't stress too much. every tank's different. just watch for algae blooms if you push higher.